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Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]31<div class="doc_author">
32 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]74code</a> produced by all aspects of the LLVM compiler and adds many <a
75href="#newfeatures">new features</a>, and <a href="#bugfix">fixes a few
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]78<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
79SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It
80has also been used to compile <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs, though it has still received less testing
82than the C front-end.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]84</div>
85
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]91<div class="doc_text">
92
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]97<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
98before it could only narrow them down to a function being miscompiled.</li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]99<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
100modes of llc</a> and lli, by passing them command line flags (e.g.,
101<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]102<li>The Control Flow Graph in the native code generators is no longer
103constrained to be the same as the CFG for the LLVM input code.</li>
104<li>The LLVM induction variable analysis routines have been rewritten.</li>
105<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
106<li>The induction variable substitution pass performs linear function test
107replacement and exit value replacement optimizations.</li>
Chris Lattner39491a72004-05-24 04:45:52 +0000[diff] [blame]108<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
109Garbage Collection</a>, enabling the use of aggressive copying and generational
110collectors.</li>
111<li>LLVM now includes an implementation of Andersen's interprocedural alias
112analysis algorithm.</li>
Chris Lattner14cd5392004-05-24 05:34:32 +0000[diff] [blame]113<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
114basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke5beb8ba2004-06-01 20:02:56 +0000[diff] [blame]115<li>LLVM and the C front-end now work under Win32 using the
116<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]117This includes the JIT compiler.</li>
Chris Lattner00f19b622004-06-04 00:40:11 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119 href="CodeGenerator.html">documented</a>.</li>
Reid Spencer624c5432004-06-08 07:30:31 +0000[diff] [blame]120<li>There is a new tool, llvm-abcd, the Analysis of ByteCode Dumper (abcd).
121This tool can compute basic statistics and bytecode density statistics on a
122module or function basis and also dump out bytecode in a textual format that
123is lower level than assembly (values are not resolved from slot numbers).
124It should only be of interest to (a) those who are working to improve the
125bytecode format and (b) those who really want to understand or document the
126details of the bytecode format.</li>
127<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
128 being documented.</li>
Chris Lattneree98bf52004-06-15 21:50:46 +0000[diff] [blame]129<li>LLVM now provides an <a href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic
Chris Lattner00cda7a2004-06-11 04:35:21 +0000[diff] [blame]130for efficient implementation of unordered floating point comparisons.</li>
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]131<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
132point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]133</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]134
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]135</div>
136
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]137
138<!--=========================================================================-->
139<div class="doc_subsubsection">
140In this release, the following missing features were implemented:
141</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]142
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]143<div class="doc_text">
144
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]145<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]146<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
147more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]148<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
149non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]150<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
151with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]152<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
153uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]154</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]155
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]156</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]157
158<!--=========================================================================-->
159<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]160<a name="qualityofimp">In this release, the following Quality of Implementation
161issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]162</div>
163
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]164<div class="doc_text">
165
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]166<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
168bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
170for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]171<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame]172<li>The spurious "WARNING: Found global types that are not compatible" warning
173produced when linking C++ programs has been fixed.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]174</ol>
175
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]176</div>
177
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]178<!--=========================================================================-->
179<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]180In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]181</div>
182
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]183<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]184<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]185<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
186-disable/enable-povray and -disable-spec</a></li>
187<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
188work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]189<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
190with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]191<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
192obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]193</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]194</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]195
196<!--=========================================================================-->
197<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]198<a name="codequality">This release includes the following Code Quality
199improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]200</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]201
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]202<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]203<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]204<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
205due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]206
207<li>The X86 backend now generates substantially better code for 64-bit integer
208and floating point operations.</li>
209
210<li>The -inline pass no longer inlines mutually recursive functions until it
211hits the inlining threshold.</li>
212
213<li>The -inline pass no longer misses obvious inlining opportunities just
214because the callee eventually calls into an external function.</li>
215
216<li>The -simplifycfg pass can now "if convert" simple statements into the new
217<tt>select</tt> instruction.</li>
218
219<li>The -loopsimplify pass can now break <a
220href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
221into multiple nested loops. This enables a variety of subsequent
222optimizations.</li>
223
224<li>The -adce pass can now eliminate calls to functions that do not not write to
225memory.</li>
226
227<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]228exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]229
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]230<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
231"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
232operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
233&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
234
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]235<li>LLVM now has infrastructure for (simple and sparse conditional) constant
236propagation of function calls. It currently supports a few math library
237functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]238
239<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
240loops</a> in the code to help C compilers whose optimizers do not recognize
241loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]242
243<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
244often spilled to constant pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]245</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]246</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]247
248<!--=========================================================================-->
249<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]250<a name="bugfix">In this release, the following bugs in the previous release
251were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]252</div>
253
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]254<div class="doc_text">
255
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]256<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]257
258<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]259<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
260asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]261<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
262incorrectly updates dominator information</a></li>
263<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
264breaks SSA form</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
266to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]267<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
268code that unwinds</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
270of the same name, both having constant pools</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
272physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]273<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattneraec5f262004-06-01 21:52:45 +0000[diff] [blame]274<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when missing external functions encountered</a></li>
Chris Lattner00cda7a2004-06-11 04:35:21 +0000[diff] [blame]275<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating point setcc X, X</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]276</ol>
277
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]278<p>Bugs in the C/C++ front-end:</p>
279
280<ol>
Chris Lattner3cf519a2004-06-20 19:08:50 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly initialized unsigned bitfields</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]282<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
283enum type</a></li>
284<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
285indexing miscompiled</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]286<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
287prototypes that take opaque structs by-value</a></li>
288<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
289length array of structures</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]290</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]291</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]292
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]293<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]294<div class="doc_section">
295 <a name="portability">Portability and Supported Platforms</a>
296</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]297<!-- *********************************************************************** -->
298
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]299<div class="doc_text">
300
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]301<p>LLVM is known to work in the following platforms:</p>
302
303<ul>
304<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
305 other unix-like systems).</li>
306<li>Sun UltraSPARC workstations running Solaris 8.</li>
307<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
308 interpreter only, no native codegen is available yet).</li>
309<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
310</ul>
311
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]312
313<p>The core LLVM infrastructure uses
314<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
315to the machine and operating system on which it is built. However, minor
316porting may be required to get LLVM to work on new platforms. We welcome your
317portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]318
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]319<p>Note that the LLVM build system does not currently support directories with
320spaces on them when running on Win32/cygwin. We strongly recommend running
321LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]322<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
323cygwin packages. By default, many important tools are not installed that
324are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]325
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]326</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]327
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]328<!--=========================================================================-->
329<div class="doc_subsection">
330In this release, the following portability problems were fixed:
331</div>
332
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]333<div class="doc_text">
334
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]335<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]336<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
337on Mac OS X</a></li>
338<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
339understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]340</ol>
341
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]342</div>
343
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]344<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]345<div class="doc_section">
346 <a name="knownproblems">Known Problems</a>
347</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]348<!-- *********************************************************************** -->
349
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]350<div class="doc_text">
351
352<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]353component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]354sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]355href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]356there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]357
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]358</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]359
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]360<!-- ======================================================================= -->
361<div class="doc_subsection">
362 <a name="experimental">Experimental features included with this release</a>
363</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]364
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]365<div class="doc_text">
366
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]367<p>The following components of this LLVM release are either untested, known to
368be broken or unreliable, or are in early development. These components should
369not be relied on, and bugs should not be filed against them, but they may be
370useful to some people. In particular, if you would like to work on one of these
371components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]372
373<ul>
374<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
375 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
376
377<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
378 it should) and not thoroughly tested.</li>
379<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
380<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
381</ul>
382
383</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]384
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]385<!-- ======================================================================= -->
386<div class="doc_subsection">
387 <a name="core">Known problems with the LLVM Core</a>
388</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]389
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]390<div class="doc_text">
391
392<ul>
393
394<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
395work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]396
397<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]398such, execution of a threaded program could cause these data structures to be
399corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]400
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]401<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]402
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]403<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]404table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]405
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]406<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
407objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]408
409<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswelld46c6962004-03-12 21:29:42 +0000[diff] [blame]410values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]411targets whose setjmp/longjmp libraries do not save and restore the entire
412register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]413</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]414</div>
415
416<!-- ======================================================================= -->
417<div class="doc_subsection">
418 <a name="c-fe">Known problems with the C front-end</a>
419</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]420
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]421<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]422<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]423
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]424<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]425<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]426<li>C99 Variable sized arrays do not release stack memory when they go out of
427 scope. Thus, the following program may run out of stack space:
428<pre>
429 for (i = 0; i != 1000000; ++i) {
430 int X[n];
431 foo(X);
432 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]433</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]434
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]435<li>Initialization of global union variables can only be done <a
436href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
437member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]438
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]439<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
440external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]441
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]442</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]443</div>
444
445<!-- _______________________________________________________________________ -->
446<div class="doc_subsubsection">
447 Notes
448</div>
449
450<div class="doc_text">
451
452<ul>
453
454<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]455
456<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]457support for floating point data types of any size other than 32 and 64
458bits.</li>
459
460<li>The following Unix system functionality has not been tested and may not
461work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]462 <ol>
463 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
464 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
465 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
466 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
467 - These functions have not been tested.
468 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]469
470<li>Although many GCC extensions are supported, some are not. In particular,
471 the following extensions are known to <b>not be</b> supported:
472 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>: As in Algol and Pascal, lexical scoping of functions.</li>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html#Asm%20Labels">Asm Labels</a>: Specifying the assembler name to use for a C symbol.</li>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.</li>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.</li>
482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]484 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]485
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]486 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]487 attribute means that the LLVM compiler ignores the presence of the attribute,
488 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]489 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]491
492 <ol>
493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
494 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]496
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]498
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]499 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500 return.<br>
501
502 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
503 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
504 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
505
506 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
507 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
508 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
509
510 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
511 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
512 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]513
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
515 Specifying attributes of variables.<br>
516 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
517 <tt>deprecated</tt>, <tt>transparent_union</tt>,
518 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]519
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]520 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
521 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
522 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]523 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]524
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]526 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]527 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]528
529 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
530 all target specific attributes.</li>
531
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
533 Other built-in functions.<br>
534 We support all builtins which have a C language equivalent (e.g.,
535 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
536 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]537 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
538 (currently ignored). We also support builtins for ISO C99 floating
539 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]540 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]541
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542 <p>The following extensions <b>are</b> known to be supported:</p>
543
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]544 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]545 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
547 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
Tanya Lattnerca26c3e2004-06-22 03:48:17 +0000[diff] [blame^]548 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
550 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
551 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
552 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
553 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
554 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
555 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.</li>
556 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
557 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]558 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]560 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
561or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]562 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]563 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]564 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
565 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
567 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
568 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
569 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Character-Escapes.html#Character%20Escapes">Character Escapes</a>: <code>\e</code> stands for the character &lt;ESC&gt;.</li>
570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
571 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
572 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate%20Keywords">Alternate Keywords</a>:<code>__const__</code>, <code>__asm__</code>, etc., for header files.</li>
573 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Incomplete-Enums.html#Incomplete%20Enums">Incomplete Enums</a>: <code>enum foo;</code>, with details to follow.</li>
574 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner25795bc2004-02-14 04:08:29 +0000[diff] [blame]575 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]576 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.</li>
577 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]578 </ol></li>
579
580</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]581
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]582<p>If you run into GCC extensions which have not been included in any of these
583lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]584
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]585</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]586
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]587<!-- ======================================================================= -->
588<div class="doc_subsection">
589 <a name="c++-fe">Known problems with the C++ front-end</a>
590</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]591
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]592<div class="doc_text">
593
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]594<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]595has not been tested as thoroughly as the C front-end. It has been tested and
596works for a number of non-trivial programs, but there may be lurking bugs.
597Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]598
599</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]600
601<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]602<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]603
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]607<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]608 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]609</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]610</div>
611
612<!-- _______________________________________________________________________ -->
613<div class="doc_subsubsection">
614 Notes
615</div>
616
617<div class="doc_text">
618
619<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]620
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]621<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
622parser is significantly more standards compliant (and picky) than prior GCC
623versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]624href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625
626<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]627 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]628 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]629 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]630 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]631
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]632<li>The LLVM C++ front-end follows the <a
633 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
634 This document, which is not Itanium specific, specifies a standard for name
635 mangling, class layout, v-table layout, RTTI formats, and other C++
636 representation issues. Because we use this API, code generated by the LLVM
637 compilers should be binary compatible with machine code generated by other
638 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
639 <i>However</i>, the exception handling mechanism used by LLVM is very
640 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]641 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]642
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]643</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]644
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645</div>
646
647<!-- ======================================================================= -->
648<div class="doc_subsection">
649 <a name="x86-be">Known problems with the X86 back-end</a>
650</div>
651
652<div class="doc_text">
653
654<ul>
Reid Spencerc08bc9a2004-06-19 18:24:05 +0000[diff] [blame]655 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
656 produce an llc tool that always enters an infinite loop due to what
657 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
658 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
659 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
660 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
661 affects other backends but it is unlikely.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]662</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]663
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664</div>
665
666<!-- ======================================================================= -->
667<div class="doc_subsection">
668 <a name="sparc-be">Known problems with the Sparc back-end</a>
669</div>
670
671<div class="doc_text">
672
673<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]674<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]675</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]676
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]677</div>
678
679<!-- ======================================================================= -->
680<div class="doc_subsection">
681 <a name="c-be">Known problems with the C back-end</a>
682</div>
683
684<div class="doc_text">
685
686<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]687
688<li>The C back-end produces code that violates the ANSI C Type-Based Alias
689Analysis rules. As such, special options may be necessary to compile the code
690(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]691problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]692
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]693<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]694cannot include special floating point numbers like Not-A-Number or
695Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]696
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]697<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]698supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]699frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]700
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]701</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]702
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]703</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]704
705<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]706<div class="doc_section">
707 <a name="additionalinfo">Additional Information</a>
708</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]709<!-- *********************************************************************** -->
710
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]711<div class="doc_text">
712
713<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]714including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]715implemented in LLVM. The web page also contains versions of the API
716documentation which is up-to-date with the CVS version of the source code. You
717can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]718the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]719
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]720<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]721us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
722lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]723
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]724</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]725
726<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]727
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]728<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]729<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]730 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]731 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
732 <a href="http://validator.w3.org/check/referer"><img
733 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
734
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]735 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]736 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]737</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]738
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]739</body>
740</html>